class Settings():
    """存储《外星人入侵》的所有设置"""

    def __init__(self):
        """初始化游戏的设置"""
        #设置屏幕
        self.screen_width =1200
        self.screen_height = 800
        self.bg_color = (230, 230, 230)

        #飞船的设置
        self.ship_speed_factor = 1.5

        #子弹设置
        self.bullet_speed_factor = 2
        self.bullet_width = 3
        self.bullet_height = 15
        self.bullet_color = 60, 60, 60
        self.bullet_allowed = 3